Assessing soil salinity with electrical conductivity and NDVI in the B-XII irrigation district, Lebrija (Sevilla)

Abstract

A method is proposed to estimate soil salinity and its relationship with NDVI at the plot scale. Soil apparent electrical conductivity (ECa) was measured with an electromagnetic induction sensor (EMI) at a commercial plot in the B-XII irrigation district, Lebrija (Seville). Bi- and three-dimensional images of soil electrical conductivity (EC) were obtained using inversion. Estimated EC showed strong relationships with soil salinity indicators (R²>70%), allowing the estimation of these indicators from the EC images. The methodology and the obtained results were evaluated using historical NDVI imagery obtained during 7 cropping seasons and allowed us to monitor the effect of soil salinity on crop development. The identification of areas where sudden soil salinization occurs, with negative effects on crop development, is relevant for informing soil, water and the crop management decision-making